JP2019052822A - In-furnace condition determination method, combustion control method, and waste incinerator - Google Patents

Abstract

To provide a method for detecting information necessary to set a burnout point within an appropriate range.SOLUTION: An in-furnace condition determination method performs processing including a video acquisition step and a calculation step. In the video acquisition step, a video containing at least the external appearance of waste placed on a boundary between a drying part 11 and a combustion part 12 is acquired from a window part provided in a side wall formed at an edge of the drying part 11 in a furnace width direction. In the calculation step, a flame combustion start position is identified on the basis of the video acquired in the video acquisition step, and whether the flame combustion start position is moving to an upstream side in a conveyance direction or moving to a downstream side in the conveyance direction is calculated.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for appropriately maintaining stable combustion in a grate-type waste incinerator that incinerates while conveying waste by a grate.

  Since a wide variety of waste is input to the waste incinerator, it is important that stable combustion can be appropriately maintained even when the properties of the input waste change. Here, the grate-type waste incinerator is divided into a drying section for drying the waste, a combustion section for burning the waste flame, and a post-combustion section for post-combusting the waste (Oki combustion). ing. However, depending on the properties of the waste, post-combustion may occur in a part of the combustion part, or flame combustion may occur in a part of the post-combustion part. In order to realize stable combustion, it is important to set the position of the burnout point, which is the end position of such flame combustion, within an appropriate range.

  Patent Document 1 discloses an incinerator in which an in-furnace camera is arranged further downstream in the transport direction than the post-combustion unit to acquire an image in the furnace. In this incinerator, by analyzing the images acquired by the in-furnace camera, the combustion position (point on the in-furnace camera side where the combustion of waste is most active) and the burn-out point are measured, and the measurement result is Based on this, the speed of the stalker (grate) is controlled.

  Patent Document 2 discloses an incinerator configured to detect the layer thickness and burnout point of waste in the furnace. In this incinerator, the oxygen content rate of the combustion air supplied through the stoker is controlled by the detection signal of either or both of the waste layer thickness and the burnout point, so that the waste layer thickness Is held at the set value, or the burnout point is held at the set position.

  Patent Document 3 discloses an incinerator in which an infrared camera is disposed on the ceiling wall in the furnace, and the temperature distribution in the furnace is detected and analyzed to detect the positions of the ignition point and the burnout point. In this incinerator, the amount of air to be supplied is adjusted for each of a plurality of blocks constituting the combustion unit based on the positions of the ignition point and the burn-out point and other data.

  In Patent Document 4, the temperature distribution in the furnace is measured, and at least one of the combustion start position and the burnout position on the grate is located in the front-rear direction with respect to a preset reference range. An incinerator that demands is disclosed. In this incinerator, it is determined whether at least one of the combustion start position and the burnout position is a reference range, a front side with respect to the reference range, or a rear side with respect to the reference range. And according to this determination result, the distribution ratio between the recirculated exhaust gas supplied from the front ceiling wall to the rear and the recirculated exhaust gas supplied from the rear wall or the rear ceiling wall to the front is changed. Is done.

Japanese Patent No. 3099229 JP 2002-206722 A JP 2003-161422 A JP 2014-167353 A

  However, as in Patent Documents 1 and 2, it is possible to control the position of the burnout point based on the information on the combustion position and burnout point described above and to put the burnout point in an appropriate range. It was difficult with a grid-type waste incinerator. Furthermore, in Patent Document 1, since the in-furnace camera is disposed at a relatively low position downstream of the post-combustion unit in the conveyance direction, it is impossible to acquire an image of the upstream side of the flame due to the flame. It becomes difficult.

  In patent document 3, it may aim at detecting the position of both an ignition point and a burnout point, and the infrared camera is arrange | positioned at the ceiling wall of the combustion part. When an infrared camera is arranged at this position, depending on the height of the flame, a flame (high temperature part) may be located between the infrared camera and the ignition point. In this case, the position of the ignition point cannot be detected. In addition, when an infrared camera is arranged on the ceiling wall, there is a possibility that it is affected by infrared rays generated by pyrolysis gas and combustion gas. Patent Document 4 describes that the combustion start position and the burn-out position are detected using a temperature distribution measured with an infrared camera in the same manner as in Patent Document 3, and thus the same problem as in Patent Document 3 Exists.

  The present invention has been made in view of the above circumstances, and a main object of the present invention is to provide a method for detecting information necessary for setting the burn-off point within an appropriate range.

  The problems to be solved by the present invention are as described above. Next, means for solving the problems and the effects thereof will be described.

  According to the first aspect of the present invention, the following in-furnace situation determination method is provided. That is, this in-furnace situation determination method is composed of a grate divided into a drying section, a combustion section, and a post-combustion section, and operates intermittently with the waste placed thereon. Is carried out with respect to the waste incinerator that conveys the gas toward the furnace outlet and supplies the primary combustion gas through the grate. This in-furnace situation determination method performs processing including a video acquisition process and a calculation process. In the image acquisition step, the appearance of the waste placed on the boundary between the drying unit and the combustion unit is at least from the window provided on the side wall formed at the end of the drying unit in the furnace width direction. Get the video that contains it. In the calculation step, the flame combustion start position is specified based on the video acquired in the video acquisition step, and it is calculated whether the flame combustion start position is moving upstream in the transport direction or downstream in the transport direction. To do.

  According to the 2nd viewpoint of this invention, the waste incinerator of the following structures is provided. That is, the waste incinerator includes a transport unit, a wind box, an imaging device, and a control device. The transport unit is composed of a grate divided into a drying unit, a combustion unit, and a post-combustion unit, and operates intermittently in a state where the waste is placed, thereby directing the waste toward the furnace outlet. Transport. The wind box is provided below each grate, and a primary combustion gas is supplied to the waste through the grate. The image pickup device is downstream of the central portion in the transport direction of the drying unit from the window provided on the side wall formed at the end of the drying unit in the furnace width direction, and transports the combustion unit. An image of the appearance of at least a part of the waste upstream of the central portion in the direction is acquired. The control device specifies a flame combustion start position based on the image acquired by the imaging device, and calculates whether the flame combustion start position is moving upstream in the transport direction or downstream in the transport direction.

  In a grate-type incinerator, it is important for achieving stable combustion that the burn-off point (end position of flame combustion), which is a boundary between combustion and post-combustion, falls within an appropriate range. Here, by the inventors of the present application, (1) the main cause that the position of the burnout point is outside the appropriate range is caused by the difference in the properties of the waste, and there is a difference between the assumed drying time and the actual drying time. (2) Therefore, the burn-out point based on the change information of the combustion position and the burn-out point where the state change occurs after a considerable time delay after the difference between the assumed drying time and the actual drying time occurs It has been discovered that it is actually difficult to control the position of. In addition, the moving direction of the flame combustion start position corresponds to the tendency of the difference between the assumed drying time and the actual drying time (that is, the appropriateness of the progress of the drying and combustion of the waste). It can be handled as information necessary to fit in the range.

  Also, since the side wall of the combustion part becomes extremely hot and it is difficult to install the window part and the imaging device, etc., by providing a window part on the side wall of the drying part, an image for identifying the flame combustion start position can be appropriately obtained. You can get it. Furthermore, since the side wall is unlikely to be affected by pyrolysis gas and combustion gas generated in the furnace, unlike the ceiling wall, an image for identifying the flame combustion start position can be acquired appropriately.

  ADVANTAGE OF THE INVENTION According to this invention, the method of detecting the information required in order to make a burnout point into an appropriate range can be provided.

The schematic block diagram of the waste incineration equipment containing the incinerator of one Embodiment of this invention. Functional block diagram of an incinerator. The three-dimensional schematic diagram of the incinerator which shows the attachment position of an imaging device. The flowchart which shows the control which a control apparatus performs in order to stabilize combustion. The schematic block diagram of the waste incineration equipment which shows a mode when a flame combustion start position moves to an upstream side. The schematic block diagram of the waste incineration equipment which shows a mode when a flame combustion start position moves downstream.

  <Overall Configuration of Waste Incineration Facility> First, a waste incineration facility 100 including an incinerator (waste incinerator) 10 of this embodiment will be described with reference to FIG. FIG. 1 is a schematic configuration diagram of a waste incineration facility 100 including an incinerator 10 according to an embodiment of the present invention. In the following description, the terms “upstream” and “downstream” mean upstream and downstream in the direction in which waste, combustion gas, exhaust gas, primary air, secondary air, circulating exhaust gas, and the like flow.

  As shown in FIG. 1, the waste incineration facility 100 includes an incinerator 10, a boiler 30, and a steam turbine power generation facility 35. The incinerator 10 incinerates the supplied waste. The detailed configuration of the incinerator 10 will be described later.

  The boiler 30 generates steam using heat generated by combustion of waste. The boiler 30 generates steam (superheated steam) by exchanging heat between the high-temperature combustion gas generated in the furnace and water with a large number of water tubes 31 and superheater tubes 32 provided on the flow path wall. The steam generated by the water pipe 31 and the superheater pipe 32 is supplied to the steam turbine power generation facility 35.

  The steam turbine power generation facility 35 includes a turbine and a power generation device (not shown). The turbine is rotationally driven by steam supplied from the water pipe 31 and the superheater pipe 32. The power generation device generates power using the rotational driving force of the turbine.

  Here, in order to perform stable power generation, it is necessary to stabilize the generation amount of steam (superheated steam) in the boiler 30. In order to stabilize the amount of steam (superheated steam) generated in the boiler 30, it is necessary to stabilize the heat input to the boiler 30. That is, in order to keep the power generation amount constant, it is necessary to stabilize the amount of heat held by the combustion gas supplied from the incinerator 10 to the boiler 30 and to keep the heat input to the boiler 30 stable.

  <Configuration of Incinerator 10> The incinerator 10 includes a dust supply device 40 for supplying waste into the furnace. The dust feeder 40 includes a waste charging hopper 41 and a dust feeder main body 42. The waste input hopper 41 is a portion into which waste is input from outside the furnace. The dust feeder main body 42 is located at the bottom of the waste charging hopper 41 and is configured to be movable in the horizontal direction. The dust supply apparatus main body 42 supplies the waste thrown into the waste throwing hopper 41 to the downstream side. The movement speed, the number of movements per unit time, the movement amount (stroke), and the stroke end position (movement range) are controlled by the control device 90. The dust feeding device may be of a type that moves at a slight angle with respect to the horizontal direction.

  The waste supplied into the furnace by the dust supply device 40 is supplied by the transport unit 20 in the order of the drying unit 11, the combustion unit 12, and the post-combustion unit 13. The transport unit 20 includes a drying grate 21 provided in the drying unit 11, a combustion grate 22 provided in the combustion unit 12, and a post-combustion grate 23 provided in the post-combustion unit 13. Yes. Therefore, the conveyance part 20 is comprised from the multistage grate. Each grate is provided on the bottom surface of each part, on which waste is placed.

  The grate is composed of a movable grate and a fixed grate arranged side by side in the waste transport direction, and the movable grate operates in the order of forward, stop, reverse, stop, etc. While transporting to the downstream side, the waste can be agitated. By increasing (decreasing) the operation speed of the movable grate, it is possible to increase (decrease) the waste conveyance speed. Moreover, the conveyance speed of a waste can be raised (decreased) by shortening (longening) the stop time of a movable grate. Moreover, the grate is arranged side by side with a gap of a size that allows gas to pass through.

  The drying unit 11 is a part for drying the waste supplied to the incinerator 10. The waste of the drying unit 11 is dried by the primary air supplied from below the drying grate 21 and the radiant heat of combustion in the adjacent combustion unit 12. At that time, pyrolysis gas is generated from the waste of the drying unit 11 by pyrolysis. Further, the waste of the drying unit 11 is conveyed toward the combustion unit 12 by the drying grate 21.

  The combustion unit 12 is a part that mainly burns the waste dried in the drying unit 11. In the combustion unit 12, the waste mainly causes flame combustion to generate a flame. Waste in the combustion unit 12, ash generated by combustion, and unburned unburned material are conveyed toward the rear combustion unit 13 by the combustion grate 22. Further, the combustion gas and flame generated in the combustion unit 12 pass through the throttle unit 17 and flow toward the rear combustion unit 13. The combustion grate 22 is provided at the same height as the dry grate 21, but may be provided at a position lower than the dry grate 21.

  The post-combustion unit 13 is a part for burning waste (unburned material) that could not be combusted in the combustion unit 12. In the post-combustion unit 13, combustion of unburned material that could not be combusted in the combustion unit 12 is promoted by the radiant heat of the combustion gas and primary air. As a result, most of the unburned material becomes ash, and the unburned material decreases. The ash generated in the post-combustion unit 13 is conveyed toward the chute 24 by the post-combustion grate 23 provided on the bottom surface of the post-combustion unit 13. The ash conveyed to the chute 24 is discharged outside the waste incineration facility 100. The post-combustion grate 23 of this embodiment is provided at a position lower than the combustion grate 22, but may be provided at the same height as the combustion grate 22.

  As described above, since the reaction that occurs in the drying unit 11, the combustion unit 12, and the post-combustion unit 13 is different, each wall surface has a configuration that corresponds to the reaction that occurs. For example, since flame combustion occurs in the combustion unit 12, a structure having a higher fire resistance level than that of the drying unit 11 is employed.

  The recombustion part 14 is a part which burns the unburned gas contained in the combustion gas. The recombustion unit 14 extends upward from the drying unit 11, the combustion unit 12, and the post-combustion unit 13, and secondary air is supplied in the middle thereof. As a result, the combustion gas is mixed and agitated with the secondary air, and the unburned gas contained in the combustion gas is burned in the reburning section 14. Combustion that occurs in the combustion section 12 and the post-combustion section 13 is referred to as primary combustion, and combustion that occurs in the recombustion section 14 (that is, combustion of unburned gas remaining in the primary combustion) is referred to as secondary combustion.

  The gas supply device 50 is a device that supplies gas into the furnace. The gas supply device 50 according to this embodiment includes a primary air supply unit 51, a secondary air supply unit 52, and an exhaust gas supply unit 53. Each supply part is comprised by the air blower for attracting | sucking or sending out gas.

  In this specification, the gas supplied for primary combustion is called primary combustion gas. The primary combustion gas includes primary air, circulating exhaust gas, and mixed gas thereof. The primary air is air taken from outside and is not used for combustion or the like (that is, excluding circulating exhaust gas). Therefore, the primary air includes a gas obtained by heating air taken from the outside. Similarly, in this specification, the gas supplied for secondary combustion is called secondary combustion gas. Secondary combustion gas includes secondary air, circulating exhaust gas, and mixed gas thereof. The definition of secondary air is the same as primary air.

  The primary air supply unit 51 supplies primary air into the furnace via the primary air supply path 71. The primary air supply path 71 is branched into a first supply path 71a, a second supply path 71b, and a third supply path 71c. A heater may be provided in the primary air supply path 71 so that the temperature of the primary air supplied to each part can be adjusted.

  The first supply path 71 a is a path for supplying primary air to the drying stage wind box 25 provided below the drying grate 21. A first damper 81 is provided in the first supply path 71a, and the supply amount of primary air supplied to the dry-stage wind box 25 can be adjusted. The first damper 81 is controlled by the control device 90.

  The second supply path 71 b is a path for supplying primary air to the combustion stage wind box 26 provided below the combustion grate 22. A second damper 82 is provided in the second supply path 71b, and the supply amount of primary air supplied to the combustion stage wind box 26 can be adjusted. The second damper 82 is controlled by the control device 90.

  The third supply path 71 c is a path for supplying primary air to the post-combustion stage wind box 27 provided below the post-combustion grate 23. A third damper 83 is provided in the third supply path 71c, and the supply amount of primary air supplied to the post-combustion stage wind box 27 can be adjusted. The third damper 83 is controlled by the control device 90.

  The secondary air supply unit 52 supplies secondary air from the upper part (ceiling part) to the air gas holding space 16 of the incinerator 10 through the secondary air supply path 72, and combustion gas is generated by the throttle unit 17. Secondary air is supplied to the direction changing portion (near the throttle portion 17). Moreover, the 4th damper 84 controlled by the control apparatus 90 is provided in the secondary air supply path 72, and the supply amount of the secondary air to each part can be adjusted.

  The exhaust gas supply unit 53 supplies (recirculates) the exhaust gas discharged from the waste incineration facility 100 into the furnace via the circulating exhaust gas supply path 73. The exhaust gas discharged from the waste incineration facility 100 is purified by a filtration type dust collector 60, and a part of the exhaust gas is incinerated from both side surfaces (the front side and the back side of the page) of the combustion unit 12 by the exhaust gas supply unit 53. Supplied to the furnace 10. The position where the exhaust gas is supplied is not particularly limited. For example, the exhaust gas may be supplied from the upper side (ceiling part) of the incinerator 10, or may be supplied only from one side surface. By supplying the exhaust gas to the incinerator 10, the oxygen concentration in the incinerator 10 is reduced, and a local excessive increase in the combustion temperature can be suppressed. As a result, generation of NOx can be suppressed. The circulating exhaust gas supply path 73 is provided with a fifth damper 85 that is controlled by the control device 90, and the supply amount of the circulating exhaust gas can be adjusted.

  As shown in FIGS. 1 and 2, the incinerator 10 is provided with a plurality of sensors for grasping the combustion state and the like. Specifically, an incinerator gas temperature sensor 91, an incinerator outlet gas temperature sensor 92, a CO gas concentration sensor 93, and a NOx gas concentration sensor 94 are provided.

  The incinerator gas temperature sensor 91 is disposed in the incinerator 10 (for example, downstream of the air gas holding space 16 and upstream of the post-combustion unit 13), and detects the gas temperature in the incinerator and controls the controller 90. Output to. The incinerator outlet gas temperature sensor 92 is disposed in the vicinity of the outlet of the incinerator 10 (for example, downstream of the recombustion unit 14 and upstream of the boiler 30), and detects the temperature of the incinerator outlet gas and outputs it to the control device 90. To do. The CO gas concentration sensor 93 is disposed downstream of the dust collector 60, detects the CO gas concentration contained in the exhaust gas (incinerator exhaust CO gas concentration), and outputs it to the control device 90. The NOx gas concentration sensor 94 is disposed downstream of the dust collector 60, detects the NOx gas concentration (incinerator exhaust NOx gas concentration) contained in the exhaust gas, and outputs it to the control device 90.

  The imaging device 95 is intended to acquire an image (still image or moving image) of the flame combustion start position. The imaging device 95 is not an infrared camera for detecting temperature or the like, but a camera for acquiring an image of the appearance of waste. In the incinerator 10, it is assumed that drying is completed at the downstream end of the drying unit 11 and flame combustion is started at the upstream end of the combustion unit 12. However, depending on the properties of the waste to be supplied (for example, the amount of water contained in the waste and the flammability of the waste), drying is completed in the middle of the drying unit 11 and flame combustion is started or burned. Even in the middle of the section 12, drying may not be completed and flame combustion may not start.

  Therefore, the imaging device 95 acquires at least an image of the boundary between the drying unit 11 and the combustion unit 12 (specifically, an image of the waste placed on the boundary). In this embodiment, in order to image the flame combustion start position even if the flame combustion start position moves significantly, the imaging range of the imaging device 95 is burned from the downstream side of the center in the transport direction of the drying unit 11. It is the range from the center of the conveyance direction of the part 12 to the upstream side. In addition, the imaging device 95 of the present embodiment is different from a general imaging device in a range downstream from the center in the conveyance direction of the combustion unit 12 (that is, the boundary between the combustion unit 12 and the rear combustion unit 13, and The post-combustion unit 13 and the like) are not included in the imaging range. Note that, depending on the shape in the furnace (for example, the length of the grate in the conveyance direction, etc.), it may be configured to acquire an image in a narrower range than the present embodiment in the conveyance direction.

  As shown in FIG. 3, the direction perpendicular to the waste conveyance direction and the vertical direction (vertical direction) is referred to as the furnace width direction. The imaging device 95 acquires an image from the side wall 11a that is a wall portion formed at the end of the drying unit 11 in the furnace width direction. Specifically, the window 11b is provided on the side wall 11a, and the imaging device 95 acquires an image through the window 11b. The window portion 11b is a portion for observing the inside of the furnace. Specifically, a part of the side wall 11a is opened, and the opening is closed with transparent (including translucent) heat-resistant glass. Part.

  The imaging device 95 is disposed on the side wall of the drying unit 11 and is inclined toward the downstream side in the transport direction in order to acquire an image on the downstream side of the drying unit 11. Further, the imaging device 95 is arranged at a position higher than the waste for the purpose of appropriately acquiring an image even when the amount of waste accumulation increases. Therefore, the imaging device 95 is disposed to be inclined downward. Note that the imaging device 95 may be arranged without being inclined as long as an image of the flame combustion start position can be acquired.

  In the present embodiment, the imaging device 95 is disposed only on one of the left and right side walls 11a, but the imaging device 95 may be disposed on both side walls 11a. Moreover, the structure which image | photographs a wide range image | video may be sufficient by arrange | positioning the several imaging device 95 by changing an angle to one side wall 11a. Or the structure which enables change of an imaging range, without stopping the incinerator 10 by arrange | positioning the imaging device 95 which can change an imaging range may be sufficient.

  <Control Performed by Control Device> The control device 90 is constituted by a CPU, a RAM, a ROM, and the like, performs various calculations, and controls the entire waste incineration facility 100. Hereinafter, combustion control performed by the control device 90 (in particular, control performed by analyzing an image acquired by the imaging device 95) will be described with reference to the flowchart of FIG. FIG. 4 is a flowchart showing the control performed by the control device in order to stabilize the combustion.

  First, the control device 90 specifies and stores the flame combustion start position based on the image acquired by the imaging device 95 (S101). The flame combustion start position is a position in the transport direction in which flame combustion starts. Since the image acquired by the imaging device 95 includes flame combustion, the flame combustion start position is determined by identifying the flame based on the luminance, hue, and the like, and determining the position of the upstream end of the flame. Can be identified. Although the flame combustion start position is not uniform in the furnace width direction, the flame combustion start position calculated by, for example, obtaining an average of the flame combustion start positions in the furnace width direction is stored.

  Next, the control device 90 determines whether or not the flame combustion start position has moved to the upstream side based on the time change of the flame combustion start position (S102). For example, when the amount of water contained in the waste supplied to the incinerator 10 is reduced or flammable waste is supplied, the drying unit 11 dries the waste (and thermally decomposes accompanying the drying). (The same applies hereinafter), the time actually required (actual drying time) is shortened. Therefore, the actual drying time becomes shorter than the expected drying time of waste that is assumed in advance (difference occurs). In this case, as shown in FIG. 5, since drying is completed in the middle of the drying unit 11, flame combustion occurs in the middle of the drying unit 11 (the flame combustion start position moves upstream). .

  If this state is left as it is, the flame combustion proceeds in the drying unit 11, so that the residence time required for the flame combustion in the combustion unit 12 is shortened, and the next to the flame combustion in the middle of the combustion unit 12. After that, the combustion starts gradually. As a result, the drying, combustion, and post-combustion positions on the grate gradually move upstream as a whole. The burn-out point (end of flame combustion) is out of the appropriate range, and stable combustion cannot be maintained.

  In order to prevent this, the control device 90 basically determines that the flame combustion start position has moved to the upstream side (in the case of Yes in S102), the waste conveying speed of the dry grate 21 ( Hereinafter, the conveyance speed is simply increased (S103). As described above, in order to increase the conveyance speed, the operation speed of the movable grate of the dry grate 21 is increased, or instead of or in addition, the stop time of the movable grate of the dry grate 21 is shortened. To do. Thereby, the situation where the combustion position of each part on a grate moves to an upstream side can be prevented. Therefore, the burn-out point can be within an appropriate range, and stable combustion can be maintained.

  The combustion that occurs in the incinerator 10 varies greatly depending on the shape and structure of the incinerator 10 and the waste that is input. Further, the target combustion state varies greatly depending on the required processing amount, the durability of the incinerator 10, and the regulations on exhaust gas. Therefore, the controller 90 determines whether or not the conveyance speed of the dry grate 21 needs to be increased, not only whether the flame combustion start position has moved upstream, but also other detection data (for example, incinerator gas temperature). It is preferable to make a determination based on detection data from the sensor 91 to the NOx gas concentration sensor 94 or the like.

  When it is determined that the flame combustion start position has not moved to the upstream side (in the case of No in S102), the control device 90 moves the flame combustion start position to the downstream side based on the time change of the flame combustion start position. It is determined whether or not (S104).

  For example, when the amount of water contained in the waste supplied to the incinerator 10 is increased or waste that is difficult to burn is supplied, the actual drying time for drying the waste in the drying unit 11 is increased. become longer. Accordingly, the actual drying time becomes longer than the expected drying time of waste that is assumed in advance (difference occurs). In this case, as shown in FIG. 6, since the drying is not completed even at the downstream end of the drying unit 11, flame combustion starts in the middle of the combustion unit 12 (the flame combustion start position moves downstream). Will be).

  If this state is left unattended, the residence time for flame combustion required in the combustion section 12 is not secured, so that the flame combustion that should be completed in the combustion section 12 is shifted to the rear combustion section 13, Post-combustion starts in the middle of the combustion section 13. As a result, the drying, combustion, and post-combustion positions on the grate gradually move downstream as a whole. The burn-out point is outside the appropriate range, and stable combustion cannot be maintained.

  In order to prevent this, when it is determined that the flame combustion start position has basically moved downstream (in the case of Yes in S104), the control device 90 reduces the transport speed of the dry grate 21 ( S105). As described above, in order to reduce the conveyance speed, the operation speed of the movable grate of the dry grate 21 is reduced, or instead of or in addition to that, the stop time of the movable grate of the dry grate 21 is lengthened. To do. Thereby, the situation where the combustion position of each part on a grate moves to the downstream side can be prevented. Therefore, the burn-out point can be within an appropriate range, and stable combustion can be maintained. Further, the control device 90 determines whether or not it is necessary to reduce the conveyance speed of the dry grate 21 based on other detection data as well as whether or not the flame combustion start position has moved downstream. Is preferred.

  Further, assuming that there is a difference between the actual drying time and the expected drying time of the waste, changing the conveyance speed of the drying grate 21 actually supplies the combustion grate 22 from the drying grate 21. This means that the properties of the waste that are being used are already different from the conventional assumptions. As a result, if the conveying speeds of the combustion grate 22 and the post-combustion grate 23 are set to the same as in the conventional state, the time required for combustion and post-combustion has already changed, so stable combustion cannot be maintained. .

  In order to prevent this, when the transport speed of the dry grate 21 is changed (Yes in S102 or S104), the control device 90 determines the property of the waste that is the cause of the change in the transport speed of the dry grate 21. The conveyance speed of the combustion grate 22 and the post-combustion grate 23 is changed according to the state of change (S106). Note that the controller 90 determines whether or not to change the conveyance speed of the combustion grate 22 and the post-combustion grate 23 and the amount to be changed, not only the amount of change in the conveyance speed of the dry grate 21, but also other detection data. It is preferable to determine based on the above.

  Next, the control device 90 adjusts at least one of the first damper 81 to the fifth damper 85 according to the state of change in the property of the waste that is the cause of the change in the conveyance speed of the dry grate 21. Thus, the supply amounts of the primary combustion gas and the secondary combustion gas are adjusted (S107). Conventionally, the supply amounts of the primary combustion gas and the secondary combustion gas are adjusted using, for example, the detection data of the NOx gas concentration sensor 94 from the gas temperature sensor 91 in the incinerator.

  On the other hand, in this embodiment, in addition to other detection data, based on the moving direction of the flame combustion start position (whether it is moving upstream or downstream), the primary combustion gas and Adjust the supply amount of secondary combustion gas. Here, when the flame combustion start position is moved upstream and the conveying speed of each grate is increased, the amount of pyrolysis gas generated is generally increased, although it is related to the properties of the waste. At the same time, the primary combustion gas (including unburned gas such as CO) generated by the primary combustion increases. Therefore, it is necessary to increase the supply amount of the primary combustion gas and the secondary combustion gas. On the other hand, if the flame combustion start position has moved downstream and the transport speed of each grate has been reduced, the amount of pyrolysis gas generated is generally reduced, although this is also related to the properties of the waste. At the same time, the primary combustion gas generated by the primary combustion is reduced. Therefore, it is necessary to reduce the supply amount of the primary combustion gas and the secondary combustion gas.

  Moreover, since the property of waste may change constantly, the control apparatus 90 performs the process after step S101 again after the process of step S107. As a result, even if the property of the waste changes, it can be corrected so that the progress of the drying and combustion of the waste is appropriate, so that the burn-out point is within an appropriate range and stable. Combustion can be maintained.

  As described above, the incinerator 10 of the present embodiment has a grate (a dry grate 21, a combustion grate 22, and a post-combustion fire) divided into a drying unit 11, a combustion unit 12, and a post-combustion unit 13. The grid 23) is configured to intermittently operate in a state where the waste is placed, thereby transporting the waste toward the furnace outlet and supplying the primary combustion gas through the grate. . In the in-furnace situation determination method of the present embodiment, processing including an image acquisition process and a calculation process is performed. In the image acquisition process, at least the appearance of the waste placed on the boundary between the drying unit 11 and the combustion unit 12 from the window 11b provided on the side wall 11a formed at the end of the drying unit 11 in the furnace width direction. Get the video that contains it. In the calculation step, the flame combustion start position is specified based on the video acquired in the video acquisition step, and it is calculated whether the flame combustion start position is moving upstream in the transport direction or downstream in the transport direction.

  In the grate-type incinerator 10, it is important in order to achieve stable combustion that the burn-out point (end position of flame combustion), which is the boundary between combustion and post-combustion, falls within an appropriate range. It was discovered by the inventor of the present application that the main cause that the position of the burnout point is out of the appropriate range is that there is a difference between the expected drying time and the actual drying time due to the difference in the properties of the waste. It was. Here, the moving direction of the flame combustion start position corresponds to the tendency of the difference between the assumed drying time and the actual drying time (that is, the appropriateness of the progress of the drying and combustion of the waste). Can be handled as necessary information to fit within a certain range.

  Moreover, since the side wall of the combustion part 12 becomes very high temperature and it is difficult to install a window part and an imaging device, the window part 11b is provided on the side wall 11a of the drying part 11 to specify the flame combustion start position. Video can be acquired appropriately. Furthermore, since the side wall 11a is unlikely to be affected by pyrolysis gas and combustion gas generated in the furnace, unlike the ceiling wall, an image for specifying the flame combustion start position can be appropriately acquired.

  Further, in the combustion control method of the present embodiment, when it is detected that the flame combustion start position has moved to the upstream side, control is performed to increase the waste conveyance speed by the dry grate 21. Further, when it is detected that the flame combustion start position has moved to the downstream side, control is performed to reduce the waste conveyance speed by the dry grate 21.

  Thereby, since the difference between the assumed drying time and the actual drying time can be reduced, the progress of the drying and combustion of the waste can be made more appropriate. As a result, it is possible to keep the burnout point within an appropriate range and maintain stable combustion.

  Moreover, in the combustion control method of this embodiment, while changing the conveyance speed of the dry grate 21, according to the state of the change of the property of the waste which is the cause of the change of the conveyance speed of the dry grate 21, a combustion flame is changed. The conveyance speed of the lattice 22 and the post-combustion grate 23 is changed.

  Thereby, not only the conveyance speed of the dry grate 21 but also the conveyance speed of the combustion grate 22 and the post-combustion grate 23 can be changed to correct the entire variation of the combustion state.

  Further, in the combustion control method of the present embodiment, at least any one of the drying unit 11, the combustion unit 12, and the post-combustion unit 13 is determined based on whether the flame combustion start position has moved upstream or downstream. The supply amount of the primary combustion gas supplied to the tank is adjusted.

  Thereby, since excess and deficiency of the gas for primary combustion resulting from changing the conveyance speed of waste can be corrected, drying, combustion, and after-combustion can be performed more appropriately.

  Moreover, in the incinerator 10 of this embodiment, the primary combustion performed in the drying part 11, the combustion part 12, and the post-combustion part 13, and the secondary combustion which burns the primary combustion gas containing the unburned gas generated by the said primary combustion Combustion is performed. In the combustion control method of this embodiment, the supply amount of the secondary combustion gas is adjusted based on whether the flame combustion start position has moved upstream or downstream.

  As a result, the progress of primary combustion (that is, the amount of primary combustion gas generated, etc.) can be estimated based on the moving direction of the flame combustion start position, and the supply amount of the secondary combustion gas is adjusted accordingly. Thus, the unburned gas contained in the primary combustion gas can be sufficiently burned in the secondary combustion.

  The preferred embodiment of the present invention has been described above, but the above configuration can be modified as follows, for example.

  In the said embodiment, it is a structure provided only with the imaging device 95 which acquires the image | video containing a flame combustion start position as an apparatus which acquires the image | video in a furnace. Instead of this, an existing imaging device (specifically, an imaging device that images a range downstream from the center of the combustion grate 22 in the conveyance direction) may be further provided.

  In the above embodiment, the process of changing the transport speed of the dry grate 21 and the supply amount of the primary combustion gas and the secondary combustion gas based on the moving direction of the flame combustion start position is performed. In addition to the movement direction, the transfer speed of the dry grate 21 and the supply amount of the primary combustion gas and the secondary combustion gas may be changed using the movement speed.

  In the above embodiment, the detection data used in the combustion control has been described with reference to the detection data of the incinerator gas temperature sensor 91, the incinerator outlet gas temperature sensor 92, the CO gas concentration sensor 93, and the NOx gas concentration sensor 94. The combustion control may be performed by omitting at least one detection data, or the combustion control may be performed by adding detection data different from the above. As another detection data, for example, the amount of boiler evaporation accompanying heat recovery from exhaust gas, or the amount of water spray cooling water when cooling by water spray can be used.

10 Incinerator (Waste incinerator)
DESCRIPTION OF SYMBOLS 11 Drying part 11a Side wall 11b Window part 12 Combustion part 13 Post-combustion part 20 Conveyance part 21 Drying grate 22 Combustion grate 23 Post-combustion grate 90 Control apparatus 95 Imaging device

Claims (6)

It consists of a grate divided into a drying part, a combustion part and a post-combustion part, and transports the waste toward the furnace outlet by operating intermittently in a state where the waste is placed. For a waste incinerator that supplies gas for primary combustion through a grate,
An image for acquiring an image including an appearance of at least the waste placed on a boundary between the drying unit and the combustion unit from a window provided on a side wall formed at an end of the drying unit in the furnace width direction. Acquisition process;
A calculation step for identifying a flame combustion start position based on the video acquired in the video acquisition step and calculating whether the flame combustion start position is moving upstream in the transport direction or downstream in the transport direction;
A method for determining an in-furnace situation characterized by performing a process including: A combustion control method for controlling combustion in a waste incinerator using the in-furnace situation determination method according to claim 1,
When it is detected that the flame combustion start position has moved upstream in the conveyance direction, control is performed to increase the conveyance speed of the waste by the grate of the drying unit,
When it is detected that the flame combustion start position has moved to the downstream side in the transport direction, control is performed to reduce the transport speed of the waste by the grate of the drying unit. . The combustion control method according to claim 2,
The grate of the combustion unit is changed in accordance with the state of change in the property of the waste that is the cause of the change of the conveyance rate of the grate of the drying unit while changing the conveyance rate of the grate of the drying unit And the combustion control method characterized by changing the conveyance speed of the grate of the post-combustion part. The combustion control method according to claim 2 or 3,
For primary combustion supplied to at least one of the drying unit, the combustion unit, and the post-combustion unit based on whether the flame combustion start position has moved upstream in the transport direction or downstream in the transport direction A combustion control method characterized by adjusting a gas supply amount. A combustion control method according to any one of claims 2 to 4, comprising:
In the waste incinerator, primary combustion performed in the drying unit, the combustion unit, and the post-combustion unit, and secondary combustion for combusting primary combustion gas including unburned gas generated in the primary combustion, Done,
A combustion control method, comprising: adjusting a supply amount of a secondary combustion gas based on whether the flame combustion start position is moving upstream in the transport direction or downstream in the transport direction. Conveying section that consists of a grate divided into a drying section, a combustion section, and a post-combustion section, and transports the waste toward the furnace outlet by operating intermittently in a state where the waste is placed When,
A wind box provided below each grate and supplied with a primary combustion gas for supplying waste through the grate;
Imaging for obtaining an image including an appearance of at least the waste placed on the boundary between the drying unit and the combustion unit from a window provided on a side wall formed at an end of the drying unit in the furnace width direction. Equipment,
A control device that identifies the flame combustion start position based on the image acquired by the imaging device and calculates whether the flame combustion start position is moving upstream in the transport direction or downstream in the transport direction;
A waste incinerator characterized by comprising:

Images